Water or steam injection systems for internal combustion engines are well known. Usually water is injected in atomized form through a nozzle in the cylinder head, or may be added to the combustible mixture. In some instances the water is heated to steam, which is then injected into the combustion chamber. Injection at or near the point of ignition lowers the initial mixture temperature and dilutes the combustible mixture at the time of ignition.
When the water is preheated, this is usually accomplished by applying a water jacket or flow path around the exhaust manifold, or some other hot portion of the engine. While this does use some of the excess engine heat, the cooling is not at the most needed location on the engine. In many instances, heat transfer is not consistent and it is difficult to match the water or steam input to the requirements of the engine, particularly at low speeds. Further, most systems require extensive modification to existing engine deisngs, or even specially designed engines.